Conventionally, a drum washing machine rotates a transverse-shaft type drum in an outer tub storing water at its bottom, washings are lifted up and dropped down by baffles arranged in the drum, and are thrown to an inner circumferential surface of the drum to realize washing.
For this structure of stirring the washings by the baffles, the washings are difficult to twine or rub against each other. Therefore, compared with a full automatic washing machine which washes the washings through rotation of a pulsator inside a washing and dewatering tank, a mechanical force acting on the washings is easy to become smaller and thus a cleaning performance is easy to lower.
Therefore, in the drum washing machine, the following structure can be adopted in order to improve the cleaning performance: a rotating body with a protruding part on a surface is arranged at an end part of the drum, and the drum and the rotating body can rotate at different rotation speeds during washing and rinsing.
A driving part that enables the drum and the rotating body to rotate can be, for example, configured in such a structure that the driving part is provided with a driving motor used for the drum and a driving motor used for the rotating body; the rotation of the driving motor used for the drum is transmitted to a rotating shaft of the drum by transmission belts and belt wheels so as to rotate the drum; and the rotation of the driving motor used for the rotating body is transmitted to a rotating shaft of the rotating body by the transmission belts and the belt wheels so as to rotate the rotating body (with reference to a patent document 1).